The information, dates and techniques in this are as accurate as I can currently offer. During the past three decades I have cared for, nurtured and observed tens of thousands of plants. With the help of many gardening friends I have attempted to offer on these pages some useful information to help you with your own garden. Gardening is sharing. Any corrections, comments or suggestions are appreciated and will improve future information.
(See also Sweet Peas and Wildflowers)
This is definitely a month for warm-season annuals, especially those that really love hot, hot, hot weather. The nights are warm, the days are long and sunny, and the temperatures are high. Keep newly planted annuals well watered until they are thoroughly rooted. Choices include dahlias, zinnias, lisianthus, petunias, lobelia, verbena, marigold, ageratum, cosmos, gomphrena, salvia, New Guinea impatiens, coleus, torenia, portulaca and begonias. Because of their quick growth and heavy flowering potential, annuals need more fertilizing than most other plants in the garden. Keep deadheading (removing spent flowers) from annuals to help them continue blooming abundantly.
Don’t be alarmed by a lot of leaf drop on mature plants. Avocados produce a lot of leaf litter nearly year round. This is a normal condition.
Be sure to keep a very thick blanket of mulch, compost or fallen leaves under mature avocadoes at all times. Avocadoes need a cool root-run for good health.
Irrigate as needed to keep the soil moist, but not wet. This is still an ok month for planting avocados, but don’t delay too long. Being sub-tropical plants, avocados prefer to be planted during the long warm part of the year. Some early-fruiting varieties, like ‘Anaheim’, ‘Hass’, ‘Littlecado’ and ‘Reed’, may have fruit ready to harvest. Remember that avocado fruit does not ripen on the tree; it must be removed and should ripen indoors at room temperature.
Continue to keep azaleas well irrigated now that the weather is warm. Azaleas are shallow rooted and dry out quickly. Avoid cultivating or allowing other plants to grow under or in competition with the roots of your azalea.
This is a great month to dig, transplant and divide these. Bearded Iris should be dug and divided about every four years (every two or three years for aggressive re-blooming varieties). If you are growing any of the new “repeat-blooming” varieties they may cycle again any time. Keep feeding these re-bloomers aggressively. Older “once-blooming” varieties can have their feeding reduced in half. Any organic fertilizer labeled for roses (by not with insecticides or other added ingredients) will do fine. This is an excellent time to plant new bearded iris from rhizomes.
Giant Whitefly infestations may still be noticeable. However, predators and parasites should also be present within the colonies. Check immature whiteflies carefully for signs of parasite activity. Flea, grub and cutworm populations may still be doing damage now. Control can be achieved by using various beneficial nematodes. These microscopic worms are applied by mixing them in a water can and drenching the area, then watering well. In the warm weather, spider mites will be noticed on many plants, such as citrus, avocado, pine, juniper, ivy and others. Release beneficial predator mites now for control all summer.
Bulbs, rhizomes, tubers, etc:
(See also Bearded Iris, Dahlias, Cannas and Tuberous Begonias)
Even in the hot temperatures of August there are bulbs blooming now in Orange County. These include Amaryllis belladonna, eucomis (Pineapple lily), hymenocallis, some true lilies, urginia (Giant Squill) and tuberose. Fancy leaved caladiums are still doing great now. Keep them well watered and fertilized and in indirect, but bright light.
Plant bearded iris rhizomes now (see Bearded Iris). Plant fall blooming Colchicum (sometimes called “autumn crocus) and lycoris now, if you can find them in nurseries.
Amaryllis belladonna, commonly called “Naked Ladies”, can be dug and divided now if necessary. The best time to do this is after the flowers have finished, but prior to the foliage growing again this fall. However, only perform this chore if it is absolutely necessary since crowded condition provide better flowering.
California Native Plants:
Be very cautious irrigating most of our native plants during the summer. Most of these are adapted to a winter wet – summer dry moisture cycle. Too frequent irrigations now (especially in soils with a clay content) will certainly cause problems.
Except for a few late-blooming varieties, you will probably be finished with your camellia fertilizing for the year. The first of three feedings to your camellia should have been applied about 4-6 weeks after it finished blooming. The second feeding is 4-6 weeks after the first and the final feeding is 4-6 weeks later again. Japanese camellias are about done with their “growth” cycle for the year and are now entering the period in which they set buds for next spring. Do not prune. Sasanqua camellias have also finished their “growth” cycle for the year and are also setting buds for next spring. Do not prune. Continue to keep camellias well irrigated now that the weather is warm. Camellias are shallow rooted and dry out quickly. Avoid cultivating or allowing other plants to grow under or in competition with the roots of your camellia.
They should still be flowering well now. Cannas are one of the longest blooming plants in a garden. Continue to keep them well watered in the hot summer weather, cannas do not like dry soil. As cannas flower you may notice that each stalk produces a cluster of flowers at the top. After this cluster finishes the stalk grows a few more inches and produces another cluster. In some varieties, this can go on for four or five clusters and last almost two months from beginning to end. When the last cluster of flowers has finished, cut the entire stalk to the soil. This stalk will never bloom again and cutting it down will encourage more stalks, and flowers, to grow. Keep this process up all summer for the best results.
Citrus should have healthy green leaves right now. Continue fertilizing for another month or two. Use a fertilizer that is rich in such trace minerals as iron, zinc, manganese, copper and others. These ingredients are usually well represented in organic fertilizers like Dr. Earth. Be especially attentive to irrigations now that the weather is warm. The best application method is probably by flooding the root basin and letting it soak in once or twice. Do not use sprinklers, especially if they wet the trunk of the tree. If not already picked, valencia oranges should still be ripe on the tree. Continue periodically checking for ants. Control them from climbing up the trunk of the tree or onto the branches immediately. Although not directly harmful to the citrus, they are “farming” such pests as scale, whitefly and mealybug, which are all common on citrus.
Clematis prefer cool roots, especially during the summer months. Do all you can, especially during this month and next, to keep them sheltered from the heat.
To insulate the roots, maintain a thick 3-4 inch layer of organic mulch over them at all times, especially now. In the warm summer weather be sure to apply more frequent irrigations. Continue fertilizing, to prepare the plant for potential late summer/fall blooms. Use a mild, organic fertilizer. If your soil is slightly alkaline (high pH) periodically alternate fertilizing with an acid product such as Cottonseed Meal.
Dahlias (tuberous types):
Plants should still be in full bloom and enjoying the warm sunny weather. Regularly cut off spent blooms to make the plants both look better and set more flowers.
Keep the taller varieties carefully staked to prevent the heavy canes from toppling over. Heavy natural cane bamboo stakes work well. Water regularly and deeply throughout the hot summer months. Flooding the soil works best; overhead watering will cause broken stems and mushy flowers. Fertilize them regularly throughout their growing and blooming period. Use a liquid or granular organic fertilizer that is low in nitrogen and high in phosphorus. Fish Bone Meal is excellent. If powdery mildew appears on the lower leaves use organic Neem oil or E-Rase.
Deciduous Fruit Trees:
Monitor the soil moisture and irrigate as needed. Flooding the soil beneath these trees or using a drip system are both excellent ways to irrigate these. Avoid the use of sprinklers and do not regularly wet the trunk of the tree to reduce the potential of certain diseases. If you want to reduce or limit the overall size of any of these trees the correct time to prune them is immediately following the fruit harvest, which may be now. Pruning in winter is important for the purpose of fruit production and tree structure. However, winter pruning will not limit the size of a tree; summer pruning will. Several varieties of peaches, nectarines, apricots and plums may still be ripening this month. Some apples and pears varieties will also be producing now.
Continue irrigating most varieties regularly according to the weather. Delicate varieties appreciate an occasional misting of the foliage, especially during warm, dry or windy periods. Continue fertilizing. Use a mild, organic fertilizer on ferns and alternate periodically with an acid type, especially in high pH soil. For most common varieties try blood meal alternated every third feeding with Cottonseed Meal. Keep checking for pests. Scale can be a problem and often goes undetected. It is often associated with ants, which need to be controlled as a part of any treatment program. On other ferns, especially staghorns, check carefully for signs of spider mites.
(See also the information under the individual plants)
Your plants should still be blooming, although probably a bit less than a couple of months ago. Keep fertilizing regularly with a balanced fertilizer or one slightly higher in phosphorus, to promote more flowering. Proper watering is still critical at this time of the year, especially for those plants in hanging baskets. Water early in the morning or in the evening and check the soil moisture most every day. Never let the soil dry out completely. During a particularly dry, hot or windy period a couple of mistings of the foliage is very beneficial. If the soil is already moist from an early morning watering (best), be careful not to soak the soil again or you will be encouraging root diseases. Groom the plant periodically by removing dead flowers and any developing seedpods. If your plants look gangly and unsightly try pruning them lightly. If you keep feeding them heavily they will put on new growth that you can pinch once or twice and then have a nice bloom again. Keep watching for any signs of Fuchsia Gall Mites this month. These nearly invisible pests are a serious threat to fuchsias. Look for any signs of puckered or distorted new growth. If you discover any, pinch it out and dispose of it immediately. A pesticide treatment is usually required.
Keep them well fed through the summer months. Use a fertilizer with trace minerals, such as most organic types and alternate this with an acidic formula to keep the pH down.
If the leaves are showing signs of green veins with yellow areas between the veins, especially on the new growth, they need additional iron. Iron is a supplement to the regular fertilizing program of your gardenia. Gardenias are shallow rooted and will dry out quickly. A thick layer of organic mulch over the roots helps moderate the soil temperatures and retain moisture. If you haven’t already, this is a good month to apply this mulch. Avoid cultivating or allowing other plants to grow under or in competition with their roots.
Gardenias do not like hot dry winds. If these occur, do what you can to shield the plant. A light misting and syringe of the leaves also helps.
This group includes Ivy geraniums, zonal geraniums (also called “Common” geraniums), Martha geraniums and the various scented geraniums, but does not include true geraniums (sometimes called “Hardy” geraniums), which are discussed under Perennials. Ivy and Zonal types are still blooming, but may be look bit heat stressed. Keep up with removing spent flowers regularly to encourage more bloom. For the most part, Martha types have finished blooming for this year. Continue fertilizing all geraniums, except most scented types, regularly with a balanced fertilizer. Geraniums prefer a slightly acidic soil, so periodically alternate feedings with an acid type, such as Cottonseed Meal.
Ivy and Zonal geraniums do not like heavy pruning. To keep the plants shapely and vigorous for a longer period of time prune back a few long stems every month or so through fall, but never very many at one time. Budworms may still be attacking the developing buds and new leaves. If necessary, spray with BT on a regular basis.
Plants are directing much of their energy now toward fruit production.
Assuming the use of a granular organic product, the feeding of grapes is in six to eight week intervals following the first application, which was applied when the new growth was just emerging. Following this schedule, four applications are usually sufficient. Grapes need a well-balanced fertilizer that contains trace minerals. Organic products usually are a good choice. Depending upon the variety, continue harvesting fruit when it is fully formed and well colored.
If birds or wildlife are a problem, protect the plants with nearly invisible black nylon netting.
Continue irrigating regularly and deeply in the warm summer temperatures. Watch for signs of powdery mildew on the foliage. Usually this is due to poor air circulation around the plant, too much shading, or the lack of a winter dormant spray. If treatment now is necessary use an organic Neem oil product.
Cool season groundcovers are showing heat stress. Keep them irrigated and mulched to help them through these warm months.
Warm season groundcovers are growing and blooming. Keep them irrigated as the weather warms.
You can still get a decent harvest of basil if you get it planted right away. Keep pinching the flowers off as they develop. Flowers not only reduce the quantity and size of the foliage, but change the flavor of basil as well. Many perennial herbs can be planted nearly year-round, even during the heat of August if they are watered carefully. These include marjoram, oregano, rosemary, sage, thyme, feverfew, lavender, lemon balm, lemon grass, lemon verbena, St. johns wort, tansy, tarragon and thyme.
Most of the flowering should be about done. Even dried hydrangea flowers can be attractive on the plant as they change color and take on a unique appearance. The first week of the month is about your last good chance to remove any flowers that have faded. Pruning by then will still give the plant enough time to produce some new growth (which is where the flowers will be next season). Prune as far as half way down the stem below the faded flower. Only prune stems that have flowered this season, leave all other stems alone since they will flower on their tips next season. Any pruning after the beginning of this month will interfere with the plants ability to bloom well next year. Don’t cut the plant again until next summer. Feed them one more time in order to produce more new growth (which will bloom next year).
Remember, cool-season lawns (fescue/Marathon, ryegrass, bluegrass) should be mowed about a half an inch higher in the warm months than in the cool months. Keep the mower at this higher setting for one more month. It’s too late to attempt to plant new cool-season lawns; wait for another month or two. Continue feeding warm-season lawns into the fall months. For the next couple of months continue reducing the dosage of fertilizer by half to cool-season lawns. Too much fertilizer right now, during the warm weather, will make these cool-season turfs very susceptible to various diseases. This is still a good month to plant warm-season lawns (hybrid bermudagrass, St. Augustine, etc.) from sod, just keep them well watered. Most warm-season grasses do not grow from seed and are best only installed from sod. Crabgrass is at it growing peak over the next month or two and the clumps are easy to notice in lawns. It will also be setting seed in the next couple of months that will potentially ensure an even larger problem next year. For small infestations water the lawn and then hand pull the clumps – they will remove fairly easily in the soggy soil. For larger infestations use a selective herbicide with the ingredient “MSMA”. Follow label directions carefully.
Orchids (outside grown):
Keep feeding cymbidiums with high nitrogen to promote growth. Be sure to keep them well watered in the warm summer months.
A few grasses will begin developing seed heads already, although most are still at least a month away. These seed heads can be quite ornamental and are one of the most ornamental aspects of these plants. Some grasses may want to re-seed either in your garden or even into an adjacent wild area. If this as an issue, prune these seed heads off before the heads are fully ripe to prevent the seeds from dispersing.
(See also Bearded Iris, Bulbs/Rhizomes/Tubers, Cannas, Dahlias, Fuchsias, Geraniums, Ornamental Grasses and Tuberous Begonias)
If you are planting perennials this month be sure to keep them well watered as these young plants head into the warm summer months. Try to avoid buying overgrown or root bound plants, as they will be harder to establish. Keep fertilizing your perennials. The frequency and amount will depend upon the formulation that you are using. If you have been building up your soil health your fertilizing duties will be much reduced. Removing spent or old flowers regularly will help them to produce more new flowers. This is especially important at this time of the year as many of these plants are attempting to set seeds. Most of your time in the perennial garden now will be occupied with general cleaning, some trimming, lots of deadheading and mostly enjoying your garden. The summer heat will take it toll on some plants while other will seem to grow even stronger.
Irrigating your perennials now is important. The heat of summer is bearing down on these plants and the plants will respond well to careful irrigations.
Begin preparing space now for new plantings, during the upcoming fall planting season.
Pests & Diseases:
(See also the information under the individual plants and Beneficial Insects)
Periodically rinsing off the foliage of the plants in your garden during the summer will significantly reduce many pest problems, especially mites and whitefly.
Places to Visit:
Gardens that look terrific almost any time of the year include Sherman Library and Gardens (Corona del Mar), The Fullerton Arboretum (Fullerton), Los Angeles Arboretum (Arcadia), Huntington Library and Botanical Gardens (San Marino) and Quail Botanical Gardens (Encinitas).
(See also the information under the individual plants)
Do not pinch or prune the plant. Keep fertilizing the plant often with a well balanced food to encourage growth. Watch for whiteflies and treat as needed. Protect the plant from high winds to avoid breaking the stems. Keep the plants well watered.
Records, Catalogs, Books and Organizations:
If you don’t already have it, this would be the month to buy a copy of the famous book on southern California gardening by Bob Smaus. Titled “52 Weeks in The California Garden”, this book begins with the month of September and is a month-by-month dialogue of the activities of a garden. This is still a terrific time to attend an educational garden seminar or meeting. Excellent programs are available and most, but not all, are free, require no memberships and no reservations. There is so much going on right now that you will have to pay close attention to keep track of it all. Continue making notes in your journal now, especially about water, and what plants are coming into bloom and which are going out of bloom. These will be useful to you next year.
Although they may still be blooming, the heat of this and next month are taking a bit of a toll on roses, especially in inland gardens. A moderate summer pruning will really help revive your roses now and will encourage a big bloom display over the next few months. Early in the month is the best time to do this pruning. Remove about 1/3 of the plant and any crossing or awkward growth. Be sure to fertilize well immediately after pruning. If you haven’t already, check the mulch layer under the roses and add more as needed. Disease should not be much of an issue now, except along the immediate coast. Rose slugs are still a problem, but should be less now. Do not use soil-applied fertilizers combined with systemic insecticide. These products are very disruptive to soil life (beneficial microorganisms, bacteria, mycorrhizal fungi, earthworms, etc.). Many rosarians also believe they reduce the vigor of the rose. Roses are heavy feeders; continue regular fertilizing. Rather than use fertilizer/insecticide combinations (which severely disrupt soil life), use a well-balanced organic product. Keep deadheading roses as they fade. Stay on the lookout for pests. Rose Slug problems may be less by now, but spider mites like the warm, dry summer temperatures. Irrigations should be frequent and deep in the warm summer weather. Hose off the foliage of roses frequently. Contrary to popular myth, this will actually reduce the likelihood of powdery mildew and discourages spider mites as well.
(See also the information under Azaleas, Camellias, Gardenias, Hydrangeas and others) In areas adjacent to brushland and wild spaces this is a good time to reduce your fuel in the event of a brushfire. Remove shrubbery and weeds that have grown too near the house. This fall, consider planting fire resistant groundcover and other plants as a buffer against fires.
We have included this section, because as you know, or will discover with more experience, a good garden begins with the soil. Investing in the soil, managing the soil and protecting the soil are not afterthoughts in a successful garden, but the foundation. Healthy soil is living and breathing, teaming with earthworms, microorganisms, beneficial fungi, bacteria, microbes and other invisible life. This section, possibly the most important topic of all will, provides some helpful guidance to good soil care. A thick layer of organic mulch, averaging about two inches, should be maintained on top of the soil just about year-round. Add additional mulch as needed to maintain this level. Applied now, a thick layer of mulch will cool the root systems from hot summer temperatures, reduce irrigations as much as half this summer, reduce weed growth, and improve both soil life and soil quality. We do not suggest the use of very high analysis fertilizers in a garden, especially phosphorus. Examples of fertilizers to avoid are synthetic versions with formulations like, 10-55-10, 10-30-10, etc. We don’t even suggest the popular 15-30-15 formula. These formulations will inhibit or even destroy much of the soil life that is so vital to a healthy sustainable soil. We also suggest that you not use soil-applied systemic fertilizer/insecticide combinations (especially popular with roses). These are very damaging to soil life. Use insecticides only when necessary and even then use the least damaging product available. Many of these products move into the soil and interfere with the invisible soil life.
If you can, begin a compost pile or purchase a compost bin. Leaves, clippings, kitchen produce scraps, and many other ingredients can be composted and returned to the garden. Home compost is one of the very best ingredients you can add to your soil. The benefits are huge in the areas of disease suppression, increasing beneficial microorganisms, improving soil structure and texture, nutrient retention and nematode suppression. Be sure that before you put a plant into the ground you have considered the soil and are doing all you can to improve it and protect its health.
If strawberries attempt to grow runners, pinch them off. Keep feeding them and they will continue to bear fruit.
Keep watching for signs of spider mites, which love the hot dry summertime. Rinsing the leaves with overhead watering occasionally will reduce this pest problem considerably.
(See also the information under Avocados, and Citrus)
Keep feeding now with a general-purpose organic fertilizer. Most tropicals and sub-tropicals have a higher need for trace minerals like iron, zinc, manganese and others. Organic fertilizers generally contain lots of these trace minerals and work especially well in the warm soil temperatures present now.
These are all growing well and many, but not all, are in bud or bloom now.
Keep them fertilized with a general-purpose organic fertilizer.
This is also a good time to plant these heat lovers like papaya, banana, mango and others. However, they will need to be kept well watered to help them get established.
Watering should be frequent now. Remember, most tropicals and sub-tropicals need quick soil drainage.
Seeds will be in good supply at the end of the month. This is an especially good time to plant seeds of early-blooming (also called “short-day”) varieties that may bloom by Christmas. These varieties include ‘Winter Elegance’ (our favorite) and ‘Early Multiflora’.
(See also the information under Avocados, Citrus, Deciduous Fruit Trees and Subtropical Fruits)
Deep water as needed according to the tree species, its age and the weather. This is a good month to “leach” the root zone beneath salt-sensitive species like Japanese Maples. This is accomplished by flood irrigating the soil very heavily and repeating it several times until the accumulated salts in the root zone are washed away from the roots.
Many trees may be suckering heavily now. Remove these suckers below ground by pulling them. If you cannot pull them, dig them to the point where they are attached to the tree and cut them flush with the root or trunk, leaving no “stub”. Many trees may be in bloom now, including Crape Myrtle, certain Coral Trees, Chinese Flame Trees, Cassia, Eucalyptus ficifolia and others. Enjoy their bloom.
Tropicals & Subtropicals:
Keep feeding now with a general-purpose organic fertilizer. Most tropicals and sub-tropicals have a higher need for trace minerals like iron, zinc, manganese and others. Organic fertilizers generally contain lots of these trace minerals and work especially well in the warm soil temperatures present now. These are all growing well and many, but not all, are in bud or bloom now. This is still a good month to plant or transplant palms and cycads.
This is also a good time to plant these heat lovers. However, they will need to be kept well watered to help them get established. Watering should be frequent now. Remember, most tropicals and sub-tropicals need quick soil drainage.
Potted, blooming plants are now available in nurseries. Plants should be in full bloom. Most tuberous begonias produce both male (single) and female (double) flowers separately, but on the same plant. Double flowers are much showier and many gardeners pinch off the single (male) flowers as they appear. Keep fertilizing regularly. They are heavy feeders, especially in containers. Use a well balanced fertilizer and periodically mix in an acid fertilizer, to keep the soil pH low. Keep them well watered, but not soggy, especially during the hot summer months. The surface of the soil should dry slightly between watering. Pinch off faded flowers regularly and rotate container grown plants to insure even growth. If powdery mildew appears treat it by improving air circulation around the plants. Usually this will correct the problem, if not use a fungicide.
This is the last chance if you are planting “fall tomatoes”. If your spring planted tomatoes are still doing well, leave them in, but they are often about done by now. Rather than trying to nurture the last few fruit off each plant, pull them out and start over now. The earlier in the month the better. Some warm-season vegetables can still be planted, but keep them well watered. At this time of the year quick-maturing or “early” varieties will often be good choices. From transplants try beans, cucumbers, eggplants, lima beans, squash and tomatoes. This is your last chance for corn, which is planted from seed. If strawberries attempt to grow runners, pinch them off. Keep feeding them and they will continue to bear fruit. Beets, carrots, chard, radish and possibly turnips can be planted just about year-round. All but chard are planted from seed only. Be extra diligent about keeping the small seeds watered in this hot weather. Check tomato plants for hornworm caterpillars. Hand pick them or use the safe and organic BT spray.
Keep tomato plants trained inside their cages or alternatively up sakes or obelisks. Since most annual vegetables are shallow rooted and quick growing, feed them regularly with a well balanced organic fertilizer. Keep the vegetable garden well watered during the hot summer. Harvest your crop frequently, before they get too large or past their most flavorful period. They will grow and mature quickly in the August heat.
Water & Irrigation:
(See also the information under the individual plants)
Periodically, rinse off the foliage of the plants in your garden during the summer. Larger shrubs, vines and trees will need a spray from a garden hose. This will cleanse the foliage of dust and some pollution. Pest problems will be reduced and the plants will “breathe” easier as well.
It is still the wrong time to be thinking about wildflowers now. However, if you will be planting again this winter keep the area free of weeds between now and then. If the area has no other plants in it do not water. Irrigations will only encourage weed growth. However, if you want to get a head start on weed control in the wildflower area try this: Irrigate the area lightly but several times a day for about 10 to 14 days. This will germinate many of the weed seeds. Once they germinate, control them with a either a very shallow Hula-Hoe (also called a “Wiggle Hoe”) or spray with a non residual herbicide like Roundup. Repeat the process a couple of times more before scattering the wildflowers, about November. You will then have far less weed seed germination.
Pruning established plants: Established wisterias need considerable pruning each year to encourage flowers and maintain a manageable plant. A good schedule for these three prunings is June, August and December. This will be the second pruning of the year. First, prevent any new growth from twining around itself in a hopeless mass. Next, cut again (as you did in June) all stems to just above the second or third bud above last years resting point. This is easy to spot by noticing the color of the outer layer of the stem/bark. Established wisterias need only an occasional deep summer watering and little, if any, fertilizer. However, iron is occasionally needed to correct chlorosis. Training young plants: Continue guiding the long, twining stems carefully in the direction that you want. Prune off any wayward stems completely at their source and eliminate stems that are tangling together. Make sure that the support you are training the plant onto is very strong, as wisterias are extremely heavy plants. Also on young plants, be sure to provide plenty of water and fertilizer it to encourage quick coverage and deep roots. It is not unusual to have some random summer and fall flowers on wisterias, especially if you are following the pruning instructions given here. Enjoy them.